Imai Ichiro, Sugioka Hikaru, Nishitani Goh, Mitsuya Tadashi, Hamano Yonekazu
Laboratory of Marine Environmental Microbiology, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Mar Pollut Bull. 2003;47(1-6):114-7. doi: 10.1016/S0025-326X(02)00415-0.
Monitorings were conducted on DSP toxins in mid-gut gland of scallop (mouse assay), cell numbers of toxic dinoflagellate species of Dinophysis, and diarrhetic shellfish poisoning (DSP) toxins in small-sized (0.7-5 microm) plankton fraction of seawater collected from surface (0 m) and 20 m depth at a station in Mutsu Bay, Aomori Prefecture, Japan, in 2000. A specific enzyme-linked immunosorbent assay (ELISA) was employed for the analysis of DSP toxins in small-sized plankton fraction using a mouse monoclonal anti-okadaic acid antibody which recognizes okadaic acid, dinophysistoxin-1, and dinophysistoxin-3. DSP toxins were detected twice in the mid-gut gland of scallops at 1.1-2.3 MU (mouse units) g(-1) on 26 June and at 0.6-1.2 MU g(-1) on 3 July, respectively. Relatively high cell densities of D. fortii were observed on 26 June and 11 September, and may only contribute to the bivalve toxicity during late June to early July. D. acuminata did not appear to be responsible for the toxicity of scallops in Mutsu Bay in 2000. ELISA monitoring of small-sized plankton fraction in seawater could detect DSP toxins two weeks before the detection of the toxin in scallops, and could do so two weeks after the loss of the bivalve toxicity by mouse assay. On 17 July, toxic D. fortii was detected at only small number, <10 cells l(-1), but DSP toxins were detected by the ELISA assay, suggesting a presence of other toxic small-sized plankton in seawater. For the purpose of reducing negative impacts of DSP occurrences, monitorings have been carried out hitherto on DSP toxins of bivalve tissues by mouse assay and on cell densities of "toxic" species of Dinophysis. Here we propose a usefulness of ELISA monitoring of plankton toxicity, especially in small-sized fraction, which are possible foods of mixotrophic Dinophysis, as a practical tool for detecting and predicting DSPs in coastal areas of fisheries grounds of bivalve aquaculture.
2000年，在日本青森县陆奥湾某监测站，对扇贝中肠腺的腹泻性贝类毒素（DSP毒素，小鼠生物测定法）、具尾鳍藻属有毒甲藻的细胞数量以及从海面（0米）和20米深处采集的海水中小型（0.7 - 5微米）浮游生物部分的腹泻性贝类毒素进行了监测。采用一种特异性酶联免疫吸附测定法（ELISA），使用识别冈田酸、鳍藻毒素 - 1和鳍藻毒素 - 3的小鼠单克隆抗冈田酸抗体，分析小型浮游生物部分中的DSP毒素。在扇贝中肠腺中，分别于6月26日和7月3日两次检测到DSP毒素，含量分别为1.1 - 2.3鼠单位（MU）/克（g(-1)）和0.6 - 1.2 MU/g(-1)。6月26日和9月11日观察到相对较高密度的具尾鳍藻，其可能仅在6月下旬至7月初对双壳贝类毒性有贡献。2000年，渐尖鳍藻似乎与陆奥湾扇贝的毒性无关。对海水中小型浮游生物部分进行ELISA监测，能够在扇贝中检测到毒素前两周以及通过小鼠生物测定法检测到双壳贝类毒性消失后两周检测到DSP毒素。7月17日，仅检测到少量有毒的具尾鳍藻，每升少于10个细胞，但通过ELISA测定法检测到了DSP毒素，这表明海水中存在其他有毒的小型浮游生物。为了减少DSP事件的负面影响，迄今已通过小鼠生物测定法对双壳贝类组织中的DSP毒素以及具尾鳍藻属“有毒”物种的细胞密度进行了监测。在此，我们提出ELISA监测浮游生物毒性，特别是对小型浮游生物部分（它们可能是兼养型具尾鳍藻的潜在食物），作为检测和预测双壳贝类养殖渔场沿海地区DSP的实用工具。
